Interplay between global regulators of Escherichia coli:: effect of RpoS, Lrp and H-NS on transcription of the gene osmC
Interplay between global regulators of Escherichia coli:: effect of RpoS, Lrp and H-NS on transcription of the gene osmC
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DOI：
10.1046/j.1365-2958.1998.00855.x
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发表时间：
1998-06-01
影响因子：
3.6
通讯作者：
Gutierrez, C
中科院分区：
文献类型：
--
作者：
Bouvier, J;Gordia, S;Gutierrez, C
大肠杆菌osmC基因的转录受生长阶段的调节。它是在进入稳定期之前的减速阶段诱导的。osmC表达由两个重叠启动子osmC（p1）和osmC（p2）指导。osmC（p2）主要由E-sigma（s）转录，E-sigma（s）是一种使用sigma（s）（RpoS）sigma因子的RNA聚合酶，负责生长期调节。osmC（p1）的转录与sigma（s）无关。亮氨酸响应蛋白（Lrp）已被证明结合的osmC启动子区在带移实验。使用osmC-lacZ转录融合的体内分析表明，Lrp影响两个启动子的表达。它通过E-sigma（s）抑制osmC（p1）的转录并激活osmC（p2）的转录。Lrp的缺乏导致在基本培养基中指数生长期间RpoS的量增加。核相关蛋白H-NS也抑制了来自两个启动子的osmC转录。但这是通过不同的机制实现的。hns（-）突变体对osmC（p2）的影响可能是由胞质中sigma（s）浓度的增加介导的，而对osmC（p1）的影响与sigma（s）无关。未检测到H-NS与启动子区DNA的结合，表明H-NS对osmC（p1）的影响也可能是间接的。
The transcription of the osmC gene of Escherichia coli is regulated as a function of the phase of growth. It is induced during the decelerating phase, before entry into stationary phase. osmC expression is directed by two overlapping promoters, osmC(p1) and osmC(p2). osmC(p2) is mainly transcribed by E-sigma(s), the RNA polymerase using the sigma(s) (RpoS) sigma factor, and is responsible for the growth phase regulation. Transcription from osmC(p1) is independent of sigma(s). The leucine-responsive protein (Lrp) has been shown to bind the osmC promoter region in band shift experiments. In vivo analysis using osmC-lacZ transcriptional fusions demonstrated that Lrp affects the expression of both promoters. It represses the transcription of osmC(p1) and activates the transcription of osmC(p2) by E-sigma(s). An absence of Lrp results in an increase in the amount of RpoS during exponential growth in minimal medium. The nucleoid-associated protein H-NS also represses osmC transcription from both promoters. However, this happens through different mechanisms. The effect on osmC(p2) is probably mediated by the increase in sigma(s) concentration in the cytoplasm of hns(-) mutants, while the effect on osmC(p1) is independent of sigma(s). No binding of H-NS to the promoter region DNA could be detected, indicating that the effect on osmC(p1 )could also be indirect.